The Earth s magnetic and gravity field play an important role in global and regional geodynamics. Satellite exploration of these fields has received great attention in recent years. Research satellites such as CHAMP and GRACE as well as the ESA explorer GOCE apply new measurement techniques, thus allowing the recovery of the gravitational and magnetic field with unprecedented accuracy and resolution, spatial as well as temporal. Combined with terrestrial observations and computer models, this data will help develop a more detailed understanding of the Earth as a system. In Germany, many of the processing, modelling and interpreting methodologies for these new observation techniques are developed under the umbrella of the R&D-programme GEOTECHNOLOGIEN, funded by the Federal Ministry of Education and Research (BMBF). The research projects focus on a better understanding of the spatial and temporal variations in the magnetic and gravity field and their relationship to the dynamics of the Earth s interior and global change processes.

This volume presents the results of the multidisciplinary studies covered by the programme for the period 2005-2008. It includes the following topics: High-accuracy gravity field models, near-real-time provision and usage of CHAMP and GRACE atmospheric sounding, sea level variations, improved GRACE gravity time series and their validation by ocean bottom pressure measurements, integration of space geodetic techniques as a basis for the Global Geodetic-Geophysical Observing System (GGOS), high-resolution magnetic field models and global magnetisation maps and time-variable gravity and surface mass processes."

In the recent years, space-based observation methods have led to a subst- tially improved understanding of Earth system. Geodesy and geophysics are contributing to this development by measuring the temporal and spatial va- ations of the Earth's shape, gravity ?eld, and magnetic ?eld, as well as at- sphere density. In the frame of the GermanR&D programmeGEOTECHNO- LOGIEN,researchprojectshavebeen launchedin2002relatedto the satellite missions CHAMP, GRACE and ESA's planned mission GOCE, to comp- mentary terrestrial and airborne sensor systems and to consistent and stable high-precision global reference systems for satellite and other techniques. In the initial 3-year phase of the research programme (2002-2004), new gravity ?eld models have been computed from CHAMP and GRACE data which outperform previous models in accuracy by up to two orders of m- nitude for the long and medium wavelengths. A special highlight is the - termination of seasonal gravity variations caused by changes in continental water masses. For GOCE, to be launched in 2006, new gravity ?eld analysis methods are under development and integrated into the ESA processing s- tem. 200,000 GPS radio occultation pro?les, observed by CHAMP, have been processed on an operational basis. They represent new and excellent inf- mation on atmospheric refractivity, temperature and water vapor. These new developments require geodetic space techniques (such as VLBI, SLR, LLR, GPS) to be combined and synchronized as if being one global instrument.

The Earth s magnetic and gravity field play an important role in global and regional geodynamics. Satellite exploration of these fields has received great attention in recent years. Research satellites such as CHAMP and GRACE as well as the ESA explorer GOCE apply new measurement techniques, thus allowing the recovery of the gravitational and magnetic field with unprecedented accuracy and resolution, spatial as well as temporal. Combined with terrestrial observations and computer models, this data will help develop a more detailed understanding of the Earth as a system. In Germany, many of the processing, modelling and interpreting methodologies for these new observation techniques are developed under the umbrella of the R&D-programme GEOTECHNOLOGIEN, funded by the Federal Ministry of Education and Research (BMBF). The research projects focus on a better understanding of the spatial and temporal variations in the magnetic and gravity field and their relationship to the dynamics of the Earth s interior and global change processes.

This volume presents the results of the multidisciplinary studies covered by the programme for the period 2005-2008. It includes the following topics: High-accuracy gravity field models, near-real-time provision and usage of CHAMP and GRACE atmospheric sounding, sea level variations, improved GRACE gravity time series and their validation by ocean bottom pressure measurements, integration of space geodetic techniques as a basis for the Global Geodetic-Geophysical Observing System (GGOS), high-resolution magnetic field models and global magnetisation maps and time-variable gravity and surface mass processes."

In the recent years, space-based observation methods have led to a subst- tially improved understanding of Earth system. Geodesy and geophysics are contributing to this development by measuring the temporal and spatial va- ations of the Earth's shape, gravity ?eld, and magnetic ?eld, as well as at- sphere density. In the frame of the GermanR&D programmeGEOTECHNO- LOGIEN, researchprojectshavebeen launchedin2002relatedto the satellite missions CHAMP, GRACE and ESA's planned mission GOCE, to comp- mentary terrestrial and airborne sensor systems and to consistent and stable high-precision global reference systems for satellite and other techniques. In the initial 3-year phase of the research programme (2002-2004), new gravity ?eld models have been computed from CHAMP and GRACE data which outperform previous models in accuracy by up to two orders of m- nitude for the long and medium wavelengths. A special highlight is the - termination of seasonal gravity variations caused by changes in continental water masses. For GOCE, to be launched in 2006, new gravity ?eld analysis methods are under development and integrated into the ESA processing s- tem. 200,000 GPS radio occultation pro?les, observed by CHAMP, have been processed on an operational basis. They represent new and excellent inf- mation on atmospheric refractivity, temperature and water vapor. These new developments require geodetic space techniques (such as VLBI, SLR, LLR, GPS) to be combined and synchronized as if being one global instrument.